1. Field of the Invention
This invention relates to a seal, and more particularly to a seal which permits limited multi-directional movement of both the adjacent structure and any member passing through the seal. In addition to permitting multi-directional movement, the integrity of the seal is maintained as against some or all of the following: air or other gases, fire (thermal conduction), water, radiation, shock or vibration between mechanical or architectural components, and sound transfer.
2. Description of the Prior Art
Maintaining a seal between two or more structures or between penetrating members and structures where each member or structure has independent and unrelated movement relative to one another has, in the past, posed a problem to the engineer. This movement may come about for a variety of reasons. For example, when pipes penetrate protective structures there may be mechanical shocks upon start-up or shut-down in addition to any thermal expansion or contraction of the pipe. There may also be seismic considerations wherein it may be desired to provide different rates or directions of movement of the structure and the member. The engineer must allow for these movements and also maintain the desired insulation requirements. A seal possessing the conformability of a liquid with the insulating protection of a solid is required.
In the past, this problem has provided a variety of answers. Annular spaces between members and structures have been packed with materials ranging from loose fiberglass, bulk refractory fiber products, flexible polyurethane products, leaded wools, etc., to lead shot. Seismic gaps and expansion joints were sealed in the same manner. However, these past and present practices represent only partial solutions to this problem.
In most cases, these materials lacked either or both the flexibility and resiliency to allow free movement in any direction while maintaining a seal. Typically, movement caused a packing of the insulating material while further movement resulted in a void between the member or structure and the packed material. This void would usually run the entire length of the member or structure and would continue to expand until it encompassed the entire area in which movement occurred, thereby broaching the insulation.